Universal grinder head



May 21, 1946'.

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H. S". JAKOBSEN UNIVERSAL GRINDER HEAD Filed June 27, `1944 MIM/rn 3 Sheets-Sheet 2 May 21, 1946. H. s. JAKoBsEN 2,400,826 v `VUNIVERSAL GINDER HEAD Filed June 27,' 1944 :s sheets-sheet s 10 Ti ci: E.

y ZKM@ kPatented May 21, 1946 UNITED STATES PATENT OFFICEr UNIVERSAL GRINDER HEAD Harry S. Jakobsen, Harrison, N. J., assignor to J i & S Tool Co., a firm composed of F. Henry Swenson and Harry S. Jakobsen, East Orange,

Application .l une 27, 1944, Serial Nin-542,350

2 Claims.

The present invention relates to grinding machines;

The principal object of the invention is to provide a micrometrically adjustable grinding machine.

It is the object of the invention to provide a grinding machine in which the position of the work relative to the grinding wheel may be micrometrically adjusted on an axis perpendicular to the aixs of the grinding wheel as well as on These and other objects are attained by mech- E anism of which a preferred embodiment is illustrated in the accompanying drawings, in Which- Figure l is a rear end view of the headstockA portion of the machine, a part of the thereof being broken away;

Fig. 2 is a plan view of the headstock; Fig. 3` is a vertical section on the line 3 3 of Fig. 1;

Fig. 4 is a side view of the headstock; Fig. 5 is a side view of the entire machine; and Fig. 6 is a plan view of the headstock and footstock.

casing Referring to Figures 5 and 6,the grinding machine herein disclosed and claimed comprises a headstock I0, a grinder head II and a footstock or Atailstock I2 (the latter may be dispensed with for certain kinds of grinding work) mounted in the usual way on table I3. Table hand wheel I4 carrying knob I5 and wheel feed hand wheel I6 carrying knob II perform the said wheels.

Referring to Figures 1 to 4 inclusive, the headstock I0 comprises a base 20 affixed totable I3 in the usual manner, a turntable mountedon the base and a pivoted head portion I0 carried b the turntable.

The base has a circular well or recess 2I formed in it, a circular aperture v22 formed in the center of said recess, and a peripheral shoulder 23 formed at the top of the wall of said recess, concentric therewith. A vertically disposed boss 24 usual functions of is fixed in said aperture, centrally disposed with respect `to said shoulder, A roller bearing 25 is carried by said shoulder, said bearing being axially aligned with said boss and designed tocarry turntable 30 rotatably with respect to said base.

Turntable 30 has a circular groove 3| formed in its under surface, said groove being adapted to receive said roller bearing 25. Turntable30 has a centrally disposed recess or well 32 formed in it, and a circular aperture 33` formed in the center of said recess, said aperture being adapted to receive boss 24, said boss projecting, in part, into recess 32. In the ring shaped space formed between said boss and the wall of said recess 32 is a ball bearing 34 adapted to maintain the turntable in axial alignment with said boss, preventing lateral displacement of said turntable.V A plate or washer 35 screwed or bolted to the top of boss 24 by means of bolt 36 holds roller bearing 34 in place against vertical displacement, and by the same token prevents vertical displacement of turntable 30. A horizontally disposed clamping screw 31 set into the side wall of base 2l] engages the turntable to prevent rotationvthereof. A peripheral shoulder 38 `formed in the lower outer edge of turntable 30, concentric with groove 3l and shoulder 23, receives a worm gear 39 which is bolted to said turntable by means of bolts 40. Said gear is concentric with groove 3l, shoulders 23` and 38 and roller bearing 25. A long shafted worm 4I positioned to engage said worin gear, is rotatably carried in a horizontal aperture 42 formed in base 20, A handwheel 43 carrying a knob '44 is carried by the worm shaft, being xed thereto by means of key 45. A sleeve 4E encloses said worm shaft and carries a pointer or indicator 41 which points to the outer periphery of handwheel 43. On said outer periphery is a Vernier scale 48. Another pointer or indicator 49 is affixed to base 20, pointing upwards towards a micrometric scale 50 carried by turntable 38.

Turntable 30 has a horizontal, elongated, rectangular depression formed in its upper portion. Transversely disposed bolt shaft 6I `is rotatably xedin apertures 62 formed in the two elongated walls 63 which iiankA or form said depression. Said apertures 62 open into circular depressions 64 formed in the outer surfaces of said walls, said depressions carrying roller bearings 65, said roller bearings rotatably carrying said bolt shaft. The head 66, and the nut 61 of said bolt shaft, prevent axial displacement not only of the bolt shaft itself, but of the roller bearings 65 as well. y

The head or work holdingportion I0 has a lower ridge or tongue through which at one end a horizontal aperture or shaft hole 'I2 is formed, said aperture being adapted to receive said bolt shaft 6|, said head portion being mounted on turntable 30 through the instrumentality of said bolt shaft and said aperture.

The head portion carries the usual draw-in collet chuck attachment consisting of a horizontally disposed hollow spindle 13, rotatably mounted in roller bearings 14 and I5 which are iixed in said head portion, a taper sleeve 'I6 and a draw bar 'I'I carried by said spindle, a collet 'I8 carried by said sleeve, internal screw threads 'I9 at the inner end of said draw bar engaging external screw threads 80 at the inner end of said collet,

and a hand wheel Bi affixed to the outer end of said draw bar.

Fixedly mounted on hollow spindle 'I3 is a bevel gear 90 which is in mesh with bevel gear 9| which latter gear is aiiixed to and rotated by flexible drive shaft 92 which, in turn, is connected with and rotated by an electric motor (not shown) lt is by this means that the entire collet attachment is caused to rotate.

' Aiixed to head portion l0, in a line perpendicular to the axis of shaft hole I2y at the other end of the head portion from shaft hole *I2 is an elongated, outwardly projecting substantially horizontally disposed anm or bar S3 being aiiixed thereto by means of screws or bolts 95. It will be noted that head portion 'I0 pivots on bolt shaft 6| and that when it does so, bar 93 moves with it as an integral part thereof. A pair of helical tension springs 05 is fastened at one end to bar 93 and at the other end to the top of vertical housing 96, said housing being integral with turntable 30. 4Said springs act to lift bar 33 and thereby to pivot head portion 'I0 on bolt shaft E I.

A crank |00 pivoted by means of horizontal pivot or pin I0| to vertical housing 90 engages the upper surface o-f bar 93 in such manner that raising its handle member |02 causes its actuating arm |03 to force bar S3 downward, thereby causing head portion 'I0 to pivot in clockwise direction around bolt shaft 6|, as seen in Figure l. It is evident that the action of the crank opposes the action of the springs.

A vertically disposed anvil-less micrometer I0 is fixed in said vertical housing 96. It comprises a thifmble or sleeve carrying a vernier scale ||2, a barrel or hub ||3 carrying a micrometric scale H14, a spindle I5 and the conventional internal micrometer parts (not shown) common to theordinary micrometer. Spindle H5 engages the upper surface of bar 93 and serves as a stop to the upward movement of said bar.

` Aiixed to head portion 70 at a distance from shaft hole F2 and axially parallel therewith, is rotatable pivot or pin |20. `l'totatably mounted on said pivot is an elongated clamp arm |2I having a split end portion |22 adapted adjustably to clamp said pivot. Aiiixed to said clamp arm axially parallel with pivot at a distance from said clamping end, is a pin |23. Rotatably mounted on said pin |23 and held thereon by means of cotter pin |23 is a. rocking arm |25 having an arcuately concave upper edge or surface |25. The upper end portions or corners are identified by the number |27. Its side edge 23 which is adjacent the non-clamping end of clamp arm |2I, is arcuately convex, carrying a graduated scale |29. A longitudinal line |30 on clamp arm |2| serves as the indicator for said scale. An arcuate slot I3! in said rocking arm adjacentto and parallel with its said side edge |28 receives clamping screw |32 which screws into said clamp anm.

A second bar or arm |33 projecting in substantially the opposite direction from clamp arm |2I is clamped to rotatable pivot |20 in the same manner as clamp arm |2|. Bar |33 too is adjustably xed on said pivot. Situated above bar |33 and serving as a stop relative thereto, s a bell crank |34, pivoted by means of pin |35 to vertical housing 90. Aixed to said bell crank, and engaging the outside surface of vertical housing 96 is a clamp screw |36.

An elongated bar |40, axially parallel to the draw-in collet chuck attachment is dovetailed into head portion l0. Aflixed to its far end is tail stock or footstock I2, its center piece |li| being in axial alignment with said draw-in collet chuck attachment. The footstock lever is given the identifying number |112. See Figure 6.

The grinder head comprises the usual parts, to wit, a motor and a drive belt (not shown), a pulley mounting said belt |43, a grinding wheel |44, a shaft (not shown) carrying said wheel and said pulley and bearings therefor (also not shown) and a housing |45. In the present eme bodiment the axis of the grinding wheel is parallel to the plane of the top of the table, as is the axis of the collet attachment.

in operation, the work |50 is inserted into the collet and drawn in in the usual way. The opposite end of the work is held by center 23| of the footstock, where a footstock is used. The work may be turned on a Vertical axis by turning hand- Wheel 43. The extent of the turn of the work may be gaged micrometrically with the aid of scales 8 and 50. When the work is positioned on the vertical axis, according to specification, clamp screw 31 is tightened and the work is rmly held in such position for the grinding operation.

The depth of cut may be limited micrometrically by proceeding as follows: crank handle |02 is raised causing crank |00 to lower head portion 'I0 around bolt shaft 6| against the action of springs 95. Micrometer H0 is adjusted in the usual way to a pre-determined setting. Crank handle |02 is now lowered, releasing head portion 'I0 and subjecting it to the influence of springs 95.

The springs will tend to pivot head portion '.'0 around bolt shaft 6| and in the direction of the grinding wheel. The pressure of the work against the grinding wheel will be a function of the strength of the upward pull of the springs. As the work is ground down, the head portion, in response to the action of the springs, will move in upward direction around bolt shaft 6|. Its movement in said direction will cease when bar 93 contacts spindle ||5 of the micrometer. This will automatically complete the grinding operation.

Should it be desired to grind down the work in accordance with a pattern, the pattern, in the present case a gear pattern |5|, is affixed to the hollow spindle 'I3 immediately above rocking arm |25, as is shown in Figures 1 and 3. The concave upper surface |26 or the upper corners |21 are adjusted to` engage the teeth |52 of said gear pattern to a depth which may be predetermined, and which may be measured by means of scale |29. The clamping screw |32 is now tightened and the rocking arm set in the determined position with respect to clamp arm |2|. When the spindle is made to rotate, the pattern will rotate with it. As each tooth |52 strikes the rocking arm, it will cause said rocking arm, and hence said clamp arm and with it the entire head portion 10 to move in a downward direction against bell crank |34 which serves as fulcrum. As the pattern continues to rotate, the rocking arm will disengage the tooth in question, and tend to move in upward direction into the space between said tooth and the tooth immediately in back of it. This upward movement would be caused by the upward pull of springs 95 as above described. The entire head portion would thus engage in reciprocal movement, This would cause the Work |50 to engage and disengage the grinding wheel according as the head portion moves upwards or downwards. This would conform the grinding operation and hence the work, to the pattern. When the interdental space is too deep for the corners |21 to contact the root of the teeth and the bottom of said interdental space, said corners |21 merely enter such space as far as they or either of them can go. In such case, the work will conform to the peripheral outlines of the pattern only. To prevent upward movement of the head portion beyond a predetermined point and to serve as fulcrum as aforesaid, the bell crank |34 is set to engage bar |33 and clamp screw |36 is tightened to hold the crank in such position.

The embodiment herein described is intended merely to illustrate the present invention and not to limit it. Modications may be incorporated into the device without departing from its prinmicrometric means adapted to adjust the position of said turntable relative to said base, workholding means pivoted to said turntable on a horizontal pivot, said work-holding means comprising a draw-in collet chuck attachment geared to a exible motor-driven shaft, a pattern mounted on said attachment, an adjustable rocker arm adjustably clamped to a horizontal pivot rotatably fixed to said work-holding means, a second, oppositely disposed arm adjustably clamped to said horizontal pivot, a bell crank adjustably fixed to said turntable and engaging and serving as a fulcrum for said second arm, and tensioning means adapted to bring said rocker arm into yieldable engagement with said pattern.

2. A grinding machine comprising a headstock and a grinder head, said headstock comprising a fixed base, a turntable mounted on said base, rotatable with respect thereto on a vertical axis, micrometric means adapted to adjust the position of said turntable relative to said base, workholding means pivoted to said turntable on a horizontal pivot, said work-holding means comprising a draw-in collet chuck attachment geared to a ilexible motor-driven shaft, a pattern mounted on said attachment, an adjustable rocker arm adjustably clamped to a horizontal pivot rotatably xed to said work-holding means, a second, oppositely disposed arm adjustably clamped to said horizontal pivot, a bell crank adjustably xed to said turntable and engaging and serving as a fulcrurn for said second'arrn, and tensioning means adapted to bring said rocker arm into yieldable engagement with said pattern, a foot stock whose center piece is in axial alignment with said draw-in collet chuck attachment and means aiiixed to said work-holding means, adapted to support said foot stock in fixed relationship to said work holding means.

HARRY S. JAKOBSEN. 

